Reflex Movement Quiz

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Questions and Answers

What initiates the stretch reflex?

Pressure on the tendon

Increased temperature in the muscle

Stretch on the muscle (correct)

Constriction of muscle fibers

Which component is NOT included in the simplest reflex arc of the stretch reflex?

Muscle spindle

Motor neuron

Sensory neuron

Connector neuron (correct)

What characterizes the phasic response of the stretch reflex?

Rapid and brief contraction (correct)

Slow muscle contraction

Inhibition of muscle fibers

Sustained muscle contraction

What happens to the muscle fiber contraction frequency when the velocity of stretch increases?

It increases Signup and view all the answers

In a tonic response to the stretch reflex, what kind of stretch is typically occurring?

Slow and sustained Signup and view all the answers

What effect does a rapid preparatory movement have on the stretch reflex when aiming for a strong application of force?

It facilitates a quick phasic response Signup and view all the answers

Which reflex is often triggered by a sudden and strong stretch on the muscle?

Phasic response Signup and view all the answers

What is the primary function of the antigravity reflex?

To stimulate extensor muscles Signup and view all the answers

Which of the following activities best benefits from a rapid preparatory movement to utilize the stretch reflex?

Vertical jumping Signup and view all the answers

What determines the type of response (phasic or tonic) in a stretch reflex?

The velocity at which the stretch occurs Signup and view all the answers

What is the anatomical basis for a reflex movement?

Reflex arc Signup and view all the answers

Which neuron is responsible for transmitting signals from the receptor to the spinal cord in a reflex arc?

Afferent neuron Signup and view all the answers

What occurs at the myoneural junction?

Termination of the efferent neuron at muscle fibers Signup and view all the answers

Which type of reflex is primarily associated with skin receptors reacting to external stimuli?

Exteroceptive reflexes Signup and view all the answers

What role do connector neurons play in a reflex arc?

Facilitate synaptic connections between afferent and efferent neurons Signup and view all the answers

Which statement accurately describes the complexity of reflex actions?

Reflex actions are complex and integrated with other control mechanisms. Signup and view all the answers

What primarily regulates the length of the muscle spindles?

Gamma efferent system Signup and view all the answers

Which factor does NOT affect the number of reflex arcs and motor units involved in a reflex action?

Volitional control by the cerebrum Signup and view all the answers

What type of reflex occurs when a horse twitches its skin in response to a fly?

Exteroceptive reflex Signup and view all the answers

What type of response do the primary endings of muscle spindles always facilitate?

Reflex contraction Signup and view all the answers

Which type of stretch reflex is most beneficial for force development during rapid movements?

Phasic stretch reflex Signup and view all the answers

How does the Golgi tendon organ (GTO) respond compared to the muscle spindle in terms of stretch sensitivity?

It requires a stronger stimulus to override the muscle spindle response. Signup and view all the answers

Which type of muscle should facilitate a co-contraction when stimulated by secondary afferents?

Extensor muscle Signup and view all the answers

What effect does placing pressure on flexor muscles during gymnastics typically have?

Inhibits movement Signup and view all the answers

Which condition is more likely to evoke a strong phasic reflex contraction?

Quick stretch or bounce Signup and view all the answers

How do secondary afferent responses differ in terms of muscle type?

They behave differently in flexor and extensor muscles. Signup and view all the answers

What can be an undesirable effect during flexibility exercises?

Evoking the stretch reflex Signup and view all the answers

What mechanism adjusts the muscle spindle threshold in anticipation of receiving a weight?

Gamma bias Signup and view all the answers

What triggers the extensor thrust reflex in humans?

Pressure against the sole of the foot Signup and view all the answers

In which situation would the flexor reflex most likely occur?

Touching a hot surface Signup and view all the answers

How does the crossed extensor reflex support the body during a leg injury?

It activates the extensor muscles of the opposite limb to support weight. Signup and view all the answers

What is the primary purpose of the flexor reflex?

To provide self-protection against harmful stimuli Signup and view all the answers

What happens during the extensor thrust reflex when preparing for a jump?

Extensor muscles of the legs contract to facilitate push-off. Signup and view all the answers

Which receptors are primarily involved in the extensor thrust reflex?

Pacinian corpuscles Signup and view all the answers

How does the body typically react to a painful stimulus in one limb as described in the crossed extensor reflex?

The opposite limb extends to help balance the weight. Signup and view all the answers

What is the key difference between the flexor reflex and the crossed extensor reflex?

The flexor reflex involves withdrawal of the affected limb; the crossed extensor reflex stabilizes the opposite limb. Signup and view all the answers

Which type of reflex involves proprioceptors that respond to changes in body position?

Extensor thrust reflex Signup and view all the answers

What is facilitated by extending the head during a handstand?

Extension in the arms Signup and view all the answers

Which reflex must be suppressed to allow the head to extend backward during a back dive?

Labyrinth righting reflex Signup and view all the answers

What is the general outcome of the flexor reflex when we experience pain?

Immediate withdrawal of the injured body part. Signup and view all the answers

Which reflex is primarily associated with modifying the actions of the lower extremities?

Labyrinthine reflex Signup and view all the answers

What action should be taken to facilitate a one-armed pull?

Flex the head and turn it away from the pulling arm Signup and view all the answers

What is the primary purpose of the Golgi tendon organs during muscle contraction?

To inhibit muscle impulses and promote relaxation Signup and view all the answers

How does head position affect arm actions?

It influences both pulling and pushing actions. Signup and view all the answers

What describes the lengthening reaction in muscles?

A sudden relaxation due to excessive tension Signup and view all the answers

What is a characteristic of volitional movement?

It is goal-directed and involves higher brain centers. Signup and view all the answers

How does the tendon reflex serve during muscle tension regulation?

It allows for gradual increase or decrease of muscle tension Signup and view all the answers

Which anatomical structure is the highest level of control in the central nervous system?

Cerebral cortex Signup and view all the answers

At what age does the tonic labyrinth reflex typically begin to be suppressed?

At 3 months Signup and view all the answers

What common misconception can occur when learning new motor skills?

The failure to suppress reflex responses Signup and view all the answers

What is the role of the extensor thrust reflex?

It helps maintain an erect posture against gravity. Signup and view all the answers

What is the role of the righting reflex in adults?

To restore balance when the body tilts Signup and view all the answers

Which reflexes contribute to the preservation of equilibrium?

Labyrinthine reflexes Signup and view all the answers

Which reflex is evident in newborn infants and facilitates extension in response to head position?

Tonic labyrinth reflex Signup and view all the answers

How do tonic neck reflexes react to head movements?

They result in opposing limb movements based on head position Signup and view all the answers

What distinguishes the tonic labyrinth reflex from the tonic neck reflex?

The location of muscle receptor stimulation Signup and view all the answers

What happens to the tonic labyrinth reflex as infants grow older?

It is gradually modified but remains as a reflex Signup and view all the answers

What response occurs during a spin involving the righting reflex?

Limbs are thrust out to restore normal head position Signup and view all the answers

What role do muscle spindles play in kinesthesia?

They contribute to the perception of position sense. Signup and view all the answers

What is the primary function of reciprocal inhibition?

To allow agonist muscles to contract without opposition. Signup and view all the answers

When does coactivation typically occur during movement?

When there is uncertainty about the movement task. Signup and view all the answers

What is one of the mechanisms for coordinated movement mentioned in the content?

Reciprocal inhibition Signup and view all the answers

What reflex is activated early during preparation for takeoff in a standing long jump?

Labyrinthine head-righting reflex Signup and view all the answers

What happens to coactivation as familiarity with a movement increases?

It decreases in favor of reciprocal inhibition. Signup and view all the answers

Which reflex is NOT mentioned as a consideration for muscle-response patterns?

Flexor withdrawal reflex Signup and view all the answers

What is indicated by the stretch reflexes in extensors during the takeoff preparation phase?

They activate in response to flexion in hip and knee joints. Signup and view all the answers

What reflex helps maintain joint stiffness during unstable postures?

Coactivation Signup and view all the answers

In the context of muscle-response patterns, what does the term 'neuromuscular analysis' refer to?

The examination of integrated actions of multiple reflexes during movement. Signup and view all the answers

What is the primary role of the premotor area located in front of the motor cortex?

Learning complex acts Signup and view all the answers

Which area is identified as the second level of control in the central nervous system?

Basal ganglia Signup and view all the answers

What does the cerebellum primarily regulate in the context of motor control?

Timing and intensity of muscle activity Signup and view all the answers

Which sensory receptors primarily contribute to kinesthesis?

Ruffini endings, Pacinian corpuscles, and Golgi tendon organs Signup and view all the answers

How does the brainstem influence muscle activity?

By containing key facilitory and inhibitory centers Signup and view all the answers

What is the lowest level of control in the central nervous system?

Spinal cord Signup and view all the answers

Why is continuous sensory stimulation necessary for voluntary movement?

It allows for accurate muscle contraction intensity. Signup and view all the answers

What does kinesthetic perception primarily rely on?

Sensory receptors in joint capsules and ligaments Signup and view all the answers

Which level of the central nervous system is responsible for the integration of completed movements?

Cerebellum Signup and view all the answers

What is the main function of the motor area located in the precentral gyrus?

Representing body movements rather than muscles Signup and view all the answers

Study Notes

Reflex Movement

Reflexes are automatic responses that occur without conscious control, integrated at various levels of the nervous system.
The reflex arc, comprising afferent and efferent neurons, connects receptors to muscles for rapid response.
The myoneural junction (motor endplate) is where axons from efferent neurons connect with muscle fibers.

Types of Reflexes

Reflexes are primarily categorized into exteroceptive and proprioceptive reflexes related to skeletal movements.
Exteroceptive reflexes involve responses to external stimuli, such as twitching from flies or blinking when an object approaches the eye.

Exteroceptive Reflexes

Extensor Thrust Reflex: Triggered by pressure on the foot, stimulating extensor muscles for push-off (used in jumping and archery).
Flexor (Nociceptive) Reflex: Protective withdrawal from pain; occurs instantly upon injury, activating muscles for rapid retraction.
Crossed Extensor Reflex: Extensor muscle activation in one limb to support body weight when the opposite limb withdraws following injury.

Proprioceptive Reflexes

Proprioceptive reflexes respond to stimuli in muscle and joint receptors, impacting body positioning.
Stretch Reflex: Involves muscle spindle activation leading to contraction of the stretched muscle and its synergists, with relaxation of antagonists.
Phasic vs. Tonic Responses: Phasic responses are quick; tonic responses are associated with sustained muscle contraction (important in postural control).

Stretch Reflex Characteristics

Stretch reflexes can be either rapid (phasic) or sustained (tonic), influenced by the velocity of muscle stretch.
The stretch reflex is integral to athletic movements and can be manipulated for force generation or accuracy in sports.

Tendon Reflex

Golgi Tendon Organ (GTO) is sensitive to tension, inhibiting muscle contraction when excessive force is detected, allowing relaxation (lengthening reaction).
GTO serves as a feedback mechanism for muscle tension regulation, pivotal for skill mastery in movements.

Labyrinth and Neck Reflexes

Tonic Labyrinth Reflex: Influences balance and posture based on head position, affecting limb movements during motor development.
Righting Reflex: Facilitates recovery from imbalance; uses limb actions to restore proper posture in response to tilting.
Tonic Neck Reflex: Involves predictable responses from neck movement stimulation, influencing limb positioning reflexively.

Applications and Implications

Reflexes can influence athletic techniques; understanding them aids in training and rehabilitation.
The interplay between emotional states and reflex responses can impact motor skill performance, especially in stressful situations.### Body Resistance to Gravity
The body employs several reflexes to counteract gravity, including the extensor thrust reflex and a static stretch reflex.
Forward and backward swaying stimulates muscular actions crucial for maintaining equilibrium.
Visual orientation and labyrinthine reflexes contribute to balance and spatial awareness.

Locomotion Reflexes

Reflex actions of the legs in four-footed animals are linked to movement coordination.
This reflex is often associated with the crossed extensor reflex.
Research primarily on dogs and cats suggests this reflex may be limited to quadrupeds, but similar mechanisms may exist in humans.
Early locomotion patterns in humans, such as crawling, mirror quadrupedal movement, influencing arm swings in bipedal gait.

Volitional Movement

Volitional movement encompasses complex interactions among various anatomical structures: cerebral cortex, cerebellum, brainstem, spinal cord, and motor pathways.
Movements are goal-directed, with the cerebral cortex providing general control and lower levels offering more specific control.
The central nervous system is organized hierarchically into five distinct control levels.

Central Nervous System: Levels of Control

Cerebral Cortex: Highest control level, responsible for voluntary movement initiation; motor area organized by body part complexity.
Basal Ganglia: Located at thalamus level, responsible for homeostasis and coordination of learned actions.
Cerebellum: Vital for sensory integration, fine-tunes muscle activity, and ensures smooth movements.
Brainstem: Contains reticular formation for arousal and physiological parameter monitoring; influences muscle sensitivity.
Spinal Cord: Lowest control level with lower motor neuron cell bodies; key in integrating nerve impulses and specific control.

Kinesthesis

Kinesthesis refers to body position awareness and joint movement perception, relying on sensory receptors in joint capsules and ligaments.
Key receptors include Ruffini endings, Pacinian corpuscles, and Golgi tendon organs.
Rapid signal transmission is critical for the central nervous system to maintain movement accuracy.
Kinesthetic perception aids in motor learning and enables modification of movement patterns.

Reciprocal Inhibition and Coactivation

Reciprocal inhibition allows agonist muscles to contract while simultaneously inhibiting antagonist muscles, promoting efficient movement.
This mechanism operates in reflexive and familiar movements, while in less familiar tasks, coactivation may occur.
Coactivation is associated with maintaining joint stiffness during instability or uncertainty in movement.

Neuromuscular Analysis

Muscle-response patterns in motor skills involve various reflexes, including stretch reflexes and tendon organ reflexes.
Each reflex has distinct receptors and expected actions that facilitate specific muscle contractions during movement phases.
Example reflexes include:
- Labyrinthine Head-Righting Reflex: Engages inner ear systems to maintain head position during movement prep.
- Stretch Reflexes: Activates in hip, knee, and ankle extensors to prepare for takeoff by facilitating muscle contraction.
- Extensor Thrust Reflexes: Support dynamic stability during movement.

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Description

Test your understanding of reflex movements and their classifications. This quiz covers concepts like the reflex arc, types of reflexes, and specific examples such as the extensor thrust and flexor reflex. Challenge your knowledge about how our nervous system processes rapid responses.